Recent results to the evaluation of the long-term effects of metal pollution in Tisza river

Abstract

In January and March 2000 two tailings dam failures occurred in the upper Tisza catchment area near Baia Mare and Baia Borsa (Romania). These resulted metal pollution of the Lápos-Szamos-Tisza and Visó-Tisza river systems. The mining accidents were followed by a flood event. Many studies reported that elevated Cu, Zn, Pb and Cd concentrations were observable in water, sediment and in soils of flooded areas as well. Mine wastewater contained large amounts of suspended solids with high metal concentrations. The aims of this study were the determination of Lakanen-Erviö extractable, easily available metal contents of the soil samples collected in 2011 from Tivadar floodplain, a pasture near Vásárosnamény, a pasture near Rakamaz and Tiszacsege floodplain along the Tisza, and the comparison of these data and the results of an earlier study in 2000.According to our results the soil profiles of Vásárosnamény, Rakamaz and Tiszacsege is considered to be polluted by Zn, Pb and Cd. Low metal concentrations were found in the soil samples originated from Tivadar floodplain that was not affected by the first tailings pond failure. According to the statistical analyses of these data it can be established that during the 11-year period the easily available Cd, Cu, Zn and Pb contents of the pasture near Vásárosnamény increased significantly. This may caused by the periodical flood events or the mobilization of the pollutants. Further investigations (solid state partitioning of metals by sequential extraction) are required to find an explanation of this increase.